Today, in many technical fields and particularly in power supply systems for vehicles, various electrical components are used to perform a variety of different functions such as communication interfacing, switching of higher electrical powers or fast switching, as for instance in an inverter for an electric motor.
The above mentioned various electrical components often require additional supply voltages which may be generated from a primary power supply such as a battery or high power battery of a vehicle.
In the following, for illustration purposes, the invention will be described with reference to a device for converting and buffering a voltage for supplying the converted or buffered voltage to at least one of the above mentioned various electrical components in a vehicle, for instance, a variety of electronic switches in a hybrid electric vehicle.
However, the invention is not so limited and may find its application in conjunction with any other type of electrical components for which a voltage should be converted or buffered on the basis of a power supply which supplies an unsuitable voltage for the respective component or which breaks down such that the buffered voltage may at least temporarily supply certain of the electrical components.
Typically, in a vehicle, for the purpose of converting voltages to supply electrical components with a different voltage with respect to the supply voltage of a battery as a power supply, capacitively working voltage converters based on charge pumps are used, since these may be built with a small number of low cost external components such as, e.g., storage capacitors.
However, the number of switching transistors in such charge pumps is often relatively high and the energy efficiency of the voltage conversion is relatively low, in particular in a case, where charge has to be pumped over multiple stages. Since external inductors are normally more expensive than simple capacitors, in practice, inductively working voltage converters based on such expensive external inductors are only employed for higher currents.
For these or other reasons, there is a need for the present invention.